Process of making camphor



Patented cc. 9', 1924. v

nrrao s'rArss JOSEPH nnnn'r, or LYONS FARMS, nnw anasmr.

PROCESS OF MAKING CAMPHOR.

No Drawing.

ful Process of Making Camphor, of which the following is a specification.

This invention relates to the making of camphor by the oxidation of isobornylesters, and the object of the invention is to accomplish this reaction in a simple, expeditious and commercial manner.

The oxidizing of isobornylesters for the production of camphorhas hitherto generally been carried out by the use of chromic acid, permanganates, etc., but these well known processes have the distinct disadvantage of requiring considerable time. Moreover, under these processes, it is necessary to carry on the oxidation in large dilution, thus necessitating the use of large cumbersome apparatus for comparatively small amounts of the product obtained.

In practicing the present invention, I make use of the oxidizing action of the hydrates of alkalies, or alkaline earths in concentrated aqueous solutions mixed with a peroxide of a heavy metal such, for example, as manganese or lead binoxide. The process may be carried out in different ways and through the use of correspondingly difi'en ent apparatus, but, for the purpose of illustration, two distinct examples will be given, one involving heating and refluxing and the other pressure. It will be understood, hov v ever, that these examples are illustrative, only, and do not define the limits of the invention.

In the first instance, the camphor may be produced by heating 10 kilograms of isobornylacetate, or the equivalent amount of any other borneolester, 10 kilogrammes of water, 10 kilogrammes of caustic soda and 20 kilogrammes of manganese binoxide. This mi x'- ture is heated in an iron reflux apparatus for substantially 10 hours, at a temperature of about 180 to 200 C., during which time the mixture is constantly stirred. The soformed camphor may be separated by distillation with steam in a practically pure form.

In the second instance, the camphor may be produced through the use of pressure by heating 10 kilogrammes of isobornylacetate, or the equivalent amount of any other borneolester, 10 kilo rammes of water, 10 kilogrammes of caustic soda and 20 kilogrammes Application and May is, 1920. Serial No. 380,951.

of manganese binoxide in an autoclave for about six hours. at a pressure of substantially 100 to 150 lbs., at atemperature of substantially 160 to 180 C, during which time the mixture is constantly stirred. Pure camphor will result.

During this reaction, the concentrated caustic solution saponifies the isbornylacetate or any of theother bornylesters to isoborneol (C H OH) and the isoborneol, in statu nascendi, is oxidized to camphor by the excess of caustic alkali in the presence of manganese binoxide or any other binoxide of a heavy metal.

In the same manner, camphene may be oxidized to camphor but the reaction is much slower.

It will be understood that the processes described may be modified as to details, or by the substitution of equivalents, without departin from the spirit or substance of the invent on, the scope of which is commensurate with the appended claims.

Having thus fully described the invention, what I claim as new and desire to secure by Letters Patent is:

1. The process of making camphor which consists in oxidizing isobornylesters by heating the same at a temperature not exceeding 200 C., while refluxing, with a solution of a hydrate of an alkaline agent in the presence of a binoxide of a heavy metal, while the mixture is constantly stirred, and then separating the camphor thus formed.

2. The process of making camphor which consists in oxidizing isobornylesters by heating the same under pressure, while refluxing, at a temperature approximately from 180 to 200 (1, with a solution of a hydrate of an alkaline agent in the presence of a binoxide of-a heavy metal while the mixture is constantly stirred and then separating the camphor thus formed. by steam distillation.

3. The process of making camphor which consists in oxidizing isobornylesters by heating the same under a pressure of approximately from 6 to 10 atmospheres, and a temperature of 100 to 180 C., with a solution of an alkaline agent in the presence of JOSEPH 'EBERT. 

